This invention relates to an electronic apparatus associated with a speech synthesizer and more particularly to a device which provides control for synthesis of speech.
As is well known, the speech synthesizer has many applications including for example, an electronic calculator which provides audible indications of calculation formula and the results of calculations, a timepiece which audibly announces updated time of the day or alarm settings, a vending machine which delivers instructions such as deposit of coins and selection of buttons in the form of human voices and an automobile which provides audible warnings indicative of a symptom or possible trouble for the driver. It is therefore expected that the speech synthesizer will be in wide use in a variety of industries.
A voice synthesis controller, a major component of the speech synthesizer, is implemented with a one-chip LSI device, which controller contains a control memory and a sound-related data memory. The contents of the sound-related data are fetched pursant to instructions stored in the control memory for synthesis of speech. Pre-stored words can be delivered in an audible form under certain conditions by the speech synthesizer alone. In the case where a microprocessor is adapted to govern the speech synthesis controller and also has the function of a timepiece or a calculator, the controller can deliver audible indications of timekeeping information or the results of calculations while being supplied wth word codes indicative of the timekeeping information or the results of calculations. However, it is possible that the above-discussed speech synthesizers may produce wrong or nonrelevant sounds upon a decline of an enabling voltage therefor. There is thus a requirement for monitoring fluctuations in the enabling voltage and preventing wrong or nonrelevant indications from being delivered.